Integrated circuits for generating input/output latency performance metrics using real-time clock (RTC) read measurement module

A data processing system with technology for generating input/output latency metrics, the data processing system comprising:

• an input/output (I/O) manager;
• an I/O device responsive to the I/O manager;
• a central processing unit (CPU) to communicate with the I/O device via the I/O manager;
• a real-time clock (RTC) in the I/O manager;
• a read measurement register in the I/O manager;
• and
• a read latency measurement module in the I/O manager, wherein the read latency measurement module comprises control logic to perform operations comprising:
• in response to receipt of read responses that complete read requests associated with the I/O device, automatically calculating read latency for the completed read requests, based at least in part on time measurements from the RTC for initiation and completion of the completed read requests;
• automatically calculating an average read latency for the completed read requests, based at least in part on the calculated read latencies for the completed read requests;
• and
• automatically updating the read measurement register to record the average read latency for the completed read requests.

A method for generating input/output latency metrics, the method comprising:

• at a read latency measurement module in an input/output (I/O) manager of a data processing system, in response to receipt of read responses that complete read requests associated with an I/O device, automatically calculating read latencies for the completed read requests, based at least in part on time measurements from a real-time clock (RTC) for initiation and completion of the completed read requests;
• at the read latency measurement module, automatically calculating an average read latency for the completed read requests, based at least in part on the calculated read latencies for the completed read requests;
• and
• automatically updating a read measurement register in the I/O manager to record the average read latency for the completed read requests.

An integrated circuit with technology for generating input/output latency metrics, the integrated circuit comprising:

• an input/output (I/O) manager to manage read requests, wherein the I/O manager complies with revision 3.0 of a Peripheral Component Interconnect Express (PCIe) base specification;
• a real-time clock (RTC) in the I/O manager;
• a read measurement register in the I/O manager;
• and
• a read latency measurement module in the I/O manager, wherein the read latency measurement module comprises control logic to perform operations comprising:
• in response to receipt of read responses that complete read requests associated with an I/O device, automatically calculating read latency for the completed read requests, based at least in part on time measurements from the RTC for initiation and completion of the completed read requests;
• automatically calculating an average read latency for the completed read requests, based at least in part on the calculated read latencies for the completed read requests;
• and
• automatically updating the read measurement register to record the average read latency for the completed read requests.